The present invention relates generally to the field of fans and, in particular, to fan modules.
Chassis are often used to contain circuit cards, such as circuit cards of telecommunications systems. In telecommunications applications, several chassis for containing circuit cards are, for example, stacked one above the other and are secured in a rack located in a central office or other location. Many of these circuit cards dissipate heat that if not removed from the cards and subsequently from the chassis, can cause the circuit cards to fail.
Many chassis are passively cooled chassis, e.g., heat is removed from the cards and chassis by a natural convection airflow induced by a temperature difference between heated air within the chassis and cooler air outside of the chassis. In one application, outside air is drawn into the chassis through openings at the bottom of the chassis. The air flows generally vertically through the chassis and over the cards so that heat is transferred from the cards to the air, thereby heating the air. The air exits the chassis through openings in the top of the chassis. However, in some stacked arrangements, the heated air flows from the top of one chassis into a chassis above, resulting in reduced heat transfer from the cards of the chassis above. Consequently, baffles are sometimes located between successively stacked chassis for directing the airflow generally horizontally so that the heated air does not flow from one chassis into a chassis above.
The natural convection airflow through some of these passively cooled chassis does not transfer enough heat from the circuit cards and chassis. Therefore, the circuit cards can overheat and fail, As a result, fans are often located on the bottom of one or more of the chassis so as to force air vertically upward through the chassis. However, problems occur when locating fans on the bottom of a chassis located immediately above another chassis for forcing air vertically through the chassis above. For example, there is typically insufficient space between the baffle and the bottom of the chassis above the baffle for locating a fan on the bottom of the chassis. If the baffle is removed, the fan draws warm air from the chassis below and forces the warm air into the chassis above, resulting in reduced heat transfer from the cards of the chassis above.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative fan arrangements.
The above-mentioned problems with locating fans on the bottoms of chassis for containing electronic components and other problems are addressed by embodiments of the present invention and will be understood by reading and studying the following specification.
One embodiment of the present invention provides a fan module having a frame. A fan is disposed within and attached to the frame so as to align with an aperture passing through the frame. A baffle having first and second inclined surfaces in opposition is disposed within the frame. The first surface is for changing the direction of a first fluid flow from the fan, and the second surface is for changing the direction of a second fluid flow so as to direct the second fluid flow through an exit of the fan module.
Another embodiment provides a method for cooling electronic component containing chassis located adjacent one another. The method includes inserting a fan module between first and second chassis located adjacent one another so that a first edge of the fan module abuts the first chassis and a second edge of fan the module abuts the second chassis. The method includes drawing air into the fan module using a fan of the fan module to create a first airflow substantially perpendicular to fronts of the first and second chassis. Directing the first airflow into the first chassis using a first inclined surface of a baffle of the fan module to remove heat from the first chassis is included in the method. The method includes directing a second airflow through the second chassis toward the first chassis to remove heat from the second chassis. Directing the second airflow substantially perpendicularly so as to flow through an exit of the fan module using a second inclined surface of the baffle in opposition to the first surface to prevent the second flow from flowing into the first chassis is also included in the method.
Further embodiments of the invention include methods and apparatus of varying scope.